reinstall Leopard with original disc

I have a 2010 MacBook Pro which was recently running High Sierra. I wish to downgrade the OS to Leopard which it came with. I have the original install disc. I want to have the original software on this computer so that I can install iWork (have those original disks too) so that I can open and save some old AppleWorks documents from some back-up CDs from an even older computer that no longer boots.I erased the hard drive and then began a series of frustrating efforts! I have tried many methods but once the MacUtilities screen comes up, and I click on reinstall, the only option is High Sierra. There is no topic to install from the original disk even though it is in the CD/DVD drive. I also tried choosing the install CD as the start-up disc but that resulted in a question mark on the screen.